Underground tunnels remain beneath this abandoned mental asylum.

A few stone foundations and an old graveyard are all that is left of this once thriving settlement in the wilds of Connecticut.

The kind of mixed-up place that drives archaeologists crazy.

The remnants of a 19th-century ironmaking complex hidden in the woods of Connecticut.

These etchings reveal the history of a long-gone quarantine site.

A former copper mine which became a truly unsuccessful prison.

An iconic steel and chrome diner from the 1940s left empty for nearly 20 years is in danger of being demolished.

137 graves holding New England's earliest residents.

A religious-themed park filled with folk art to bring biblical stories to life that fell into disrepair and now being restored.

Quirky castle designed by the American actor best known for portraying Sherlock Holmes on stage.

American artist J. Alden Weir purchased this 60-acre estate for $10 and a painting.

The former home of Samuel Clemens and family remembers the happiest period of the author's life.

House used in the 1971 horror film "Let's Scare Jessica to Death."

Connecticut grave of the woman responsible for the Winchester Mystery House in California.

This picturesque Victorian ghost town was once a thriving mill community.

Inside a state forest, the forgotten remains of a Cold War defensive installation.

This abandoned psychiatric hospital once housed more than 4,000 patients in the middle of a quaint New England town.

A miniature village lies nearly forgotten in the forest by the side of a major highway.

An abandoned 146-acre summer resort slowly being reclaimed by nature.

Hidden behind a Target are pillows of cooled lava that formed at the bottom of a deep lake in the Mesozoic Era.

The cave where two British judges hid in exile after sentencing the king to death.

An abandoned Victorian-era mill in the middle of modern Manchester.

The once abandoned ruins of a Victorian beachside amusement park are now back in working order.

Ruins of a historic medical facility sits eerily by the water.